Heat transfer device



June 16, 1942. w. w. HIGHAM' 2,286,271

HEAT TRANSFER/D/EFIIICE Filed Mrch 7, 1940 3 Sheets-Sheet 1 INVENTOR.

151 2 f William W m' wam I gmw June 1942- V w. w. HIGHAM v 2,286,271'

HEAT TRANSFER DEVICE Filed March '7, 1940 Y s Sheets-Sheet 2 ATTO June.16; 1 w. w. HIGHAM HEAT TRANSFER DEVICE Filed March 7, 1940 3Sheets-Sheet 3 6a INVENTOR. [4 1 Ilium #T'gZn/n rATuki Patented June 16,1942 HEAT TRANSFER DEVICE William W. Higliam, Detroit, Mich., assignorto Universal Cooler Corporation, Detroit, Mich, a

corporation of Michigan Application March 7, 1940, SerialNo. 322,689

11 Claims.

This invention relates to a heat transfer device, and particularly onebelieved to be useful for heat transfer in connection with refrigerationor air conditioning. Y

Among the objects of the invention is the provision of an efiicient heattransfer device, the basic structure of which comprises a single lengthof material, which provides one or more conduits for a fluid and a largenumber of radiating elements integral therewith, and which afford alarge area for contact with the ambient atmosphere or other fluid. Thestructure is preferably such that the ambient atmosphere or other fluidis deflected or given a certain turbulence, as it is caused to pass byor through the device. Other objects will become better appreciated asthe detailed "description progresses in conjunction with theaccompanying drawings which show devices for carrying out the invention.

Fig. 1 is a plan view of a strip of material for the making of a heatexchange unit.

Fig. 2 is an. enlarged icross .sectional view cross section showing adevice constructed in accordance with the invention.

Fig. 4 is a view of a portion of a length of stock prior to theformation of the heat transfer fins.

Fig. 5 is an endview of the device as shown in Fig. 3, with some partscut away and parts shown in section.

Fig. 6 is an enlarged detailed view taken substantially on line 66 ofFig. 3.

Fig. '7 is a view illustrating a modified arrangement of heat transferwing or fin.

Fig. 8 is a view of a portion of a strip illustrating another modifiedarrangement of heat transfer fin or wing.

Fig. 9 is a view of the fin structure formed from the modifiedarrangement of Fig. 8.

Fig. 10 is a cross sectional view of a strip of stock similar to Fig. 2but illustrating a double conduit formation.

Fig. 11 is a view similar to Fig. 10 showing a further increased numberof conduits.

Fig. 12 is a partial side elevational view, with some parts cut away andsome in section, showing a heat exchange unit formed of a strip of stockwith multiple conduits.

Fig. 13 is a sectional view taken substantially on line l3- -l3 of Fig.12.

Fig. 14 is an end view of a device illustrating a series connection ofmultiple tubes.

Fig. 15 is a view taken substantially at right angles to Fig. 14.

Fig. 16 is a partial side elevational view showing a modified form offrame arrangement for the device.

Fig. 17 is a view looking substantially in the direction of arrowsl'|-l'l of Fig. 16.

The basic structure of the'heat exchange unit preferably comprises asingle length of stock which in cross section presents a tubularformation to constitute a conduit and certain fin or wing structure.Where the stock can be made in adequate lengths, a heat exchange unitwill comprise essentially one integral piece of stock, although it is tobe understood that where desired or where the size of the heat exchangeunit is large, that two or more pieces of such stock may. be united.This piece of stock is preferably extruded and is preferably aluminum oraluminum alloy, or other metals which are adaptable to the extrusionprocess. The strip is generally indicated at I, and, as shown in Fig. 2,has a hollow or tubular formation 2. It-likewise has opposite flanges 3and 4 and opposite flanges 5 and 6 with internal flanges of projectionsI and 8. These flanges run lengthwise of the extruded stock.

A length of this stock is shaped into the desired form as will presentlybe indicated, but prior to such shaping some of the flanges, such as theflanges 5 and 6, are treated and fashioned so as to form heat transferdevices which may be termed wings or flns. As shown in Fig. 4 theflanges 5 and 6 are preferably cut or slotted with a T-shaped slot tothus provide separate wings 5a and 6a integrally connected with the tubeby the metal lying between the ends of the cross bars of the T slots,this metal being indicated at 9. The wings thus formed are now twistedor fashioned until they are given a shape substantially as illustratedin Fig. 2; that is to say, a portion of the wing is bent upwardly and aportion is bent downwardly as Fig. 2 is viewed. This treatment iscontinued for the length of the stock. Moreover, the external flangesare removed at spaced points as indicated in Fig. 2.

A strip of stock thus treated may now be fashioned to form a relativelycompact heat exchange body, the preferred form being illustrated in Fig.3. The strip is fashioned by being bent at the 10- cations, where theflanges are removed, through 1 substantially andthis provides aplurality of substantially parallel runs joined by the bends which areindicated at l0. Considering the lowermost run of Fig. 3, the wings 6aare shown on the lower side of the tube and the wings a on the upperside. When the stock is reversely bent to form the run next above, thewings 5a on the next above run are caused to substantially register withthe wings So on the lowermost run as indicated. In the run second fromthe bottom, the wings 5a are on the under side of thetube formation, andthe wings So on the upper side. This condition reverses itself for thethird run and so on through the device. In other words, the wings 5a onsome runs substantially register with wings in on adjacent runs and thewings 5 Go on some runs substantially register with wings 6a on adjacentruns. In this form all of the wings are fashioned or bent in the samemanner, with the result that when the wings on opposite runs aresubstantially registered with each other, their relative condition isreversed and they more or less cross each other after the manner shownin Fig. 6.

Suitable couplings or connections may be made at the ends of the tubularformation, and I to this end terminal pieces II and 12 may be secured tothe endsby means of a welding, brazing or similar process, and a fittingI! may be placed on one or both ends. A frame structure may be placedover this arrangement to aid in the support thereof, and thisadvantageously may take the form of a strip of sheet metal fashioned toform a top l5 and legs l6 and IT, provided with I supporting feet l8.The legs are apertured, as shown at 20, for the passage of the bends intherethrough. The fitting l3 may be applied to the outside of the frameafter the frame has been located. While the part l5 has been termed thefluid within the tube contacts with the internal r In Fig. 7 a modifiedfin arrangement is shown. In this form the direction of the bending orfashioning ofthe wings 6b is reversed for each 5b, and this conditionexists throughout the unit.-

As a result, as indicated, the meeting wings 5b and 61), instead ofcrossing each other as shown in Fig. 6, substantially align with eachother and extend in the same direction. This arrangement, it isbelieved, would create a lesser agitation of the air or fluid passingthrough the device.

Other parts shown in Fig. 7 which are the same as those previouslydescribed bear the same reference characters.

A further modification is shown in Figs. 8 and a 9. Here the T slotsbetween the wings have quite a short cross bar to provide an increasedamount of integral metal 9a, which connects the wings 5c and 60, to thetubular formation. This addi-.-

tional metal provides for more transference of heat. The wings thusformed cannot be bent so abruptly as those previously described'becauseof the excess of the metal at 9a. But in this case the wings arefashioned with a more or less progressive twist, as indicated in Fig. 9,the wings thus having sort of a helical formation.

The structure may be formed from strip stock having two or more tubularformations, and this form of the invention is shown in Figs. 10 to 15.In Fig. 1Q, an extruded metal form having two tube formations is shown,the tubular formations being illustrated at 2. and the .leading andtrailing flanges at 3 and 4', with the internal flanges fins 1 and a, aswell'as the tube wall, while the atmosphere or other fluid firstcontacts with the flange 3 and directly with the tube 2 and the theintegral metal comprising the tube walls, and the fins 3 and I, and! andI, and the fins 5a and 6a. No joint .or separation is present in themetal. Where this device is used as a condenser in the refrigerating orair conditioning system, the refrigerant may be passed through passthrough the open-like structure as viewed in Fig. 3, either by the meansof a forcing device such'as a fan or the like,-or by a natural flow dueto convection currents or otherwise. Where the device is used, forexample, as a cooling unit, say

the tube formation and atmosphere caused to.

of a commercial refrigerator or anair conditioning apparatus, therefrigerant may pass through the tubular formation and the air passedover and through the outside for cooling purposes.

at 'l' and 3', while the wing-forming flanges are at 5' and 8', therebeing an integral interconnecting web 25. Fig. 11 shows a similarstructure with four tubular formations to which the same characters areapplied as are used in Fig. 10, this structure having, in addition to thweb 25, two other webs 23 and 21.

12 is a view of a unit fashioned from the four-tube type, and it will beundersood that this 'unit is made in the same manner asv the unitfashioned from a single strip previously described, the flanges beingremoved for the return bends I ll and the flanges 5' and 6 cut to formwings 5" and 6". The frame structure may be the same as that shown inFigs. 3 and 5, except it is of increased width to accommodate the widerstock, and having a top strip I5 and side legs l6 and I1 provided withopenings for the bends in the stock. The tubular formations may beconnected in parallel or in series. In Fig. 12 a header is shown at oneend of the stock and a header 3| at the other into which the .ends ofthe tubular formations connect, and the headers may be equipped withinlet and outlet couplings 33 and 34. The connection into the headersmay be made by terminal pieces 35, as indicated in Fig. 13. The seriesconnection is shown in Figs. 14 and 15, these views showing the doublestock, although it will be readily understood by those skilled in theartthat the same arrangement may be performed with strip stock havingmore than two tubular formations- In this form one side of the frame isshown at. i6", while the inlet fitting is at 35, and the outlet fittingis at 36. Fluid entering at 35 passes down one tubular form and-thenthrough may be so arranged. The reference characters employed are thesame as those employed on corresponding parts in the form shown in Fig.3.

Instead of entirely removing the flanges 3 and 6 at the bends |ll,'theyare merely cut or severed from the tube and remain attached. The flangeson one run are turned downwardly (as Fig. 16 is viewed) as at 40, whilethe flanges on other runs are turned upwardly as at M.

And these portions are preferably arranged to overlap as indicated andare secured together as by means of spot welding or the like asindicated. The lowermost run may have its flanges fashioned downwardlyandthen formed to provide a supporting foot 62. Thus with this structurethe parts of a unit are reduced to practically a minimum comprising onlythe tubular formation with its integral fins or wings with the necessaryterminals.

The structure of the heat transfer device thus described is comprised ofa minimum number of parts, is simple in construction and can bemanufactured with considerable feasibility. In addi tion to that, alarge'area for contact with the outside air or fluid is provided withsome turbulence or agitation given thereto, while at the same time themetalthrough which the heat transfer is made is integral, there being nojoints or breaks through which the heat must pass. This, of course,leads to high efliciency in the transfer of heat. It is thought thatthis arrangement is particularly useful as a condenser for refrigeratingapparatus or air conditioning apparatus, as well also as an evaporatoror cooling unit for certain. types of refrigerators and refrigeratedshow cases and the like. Of course, the apparatus is not to be limitedto such uses. In some claims reference is made to thedevice being forrefrigeration, and this is to include air conditioning.

I claim: a

l. A heat transfer device comprising, a length of metal stock having atubular formation fashioned into a plurality of spaced runs with theruns connected by reversely bent parts of the stock, aid stock havingflanges the runs thereof positioned so that the flanges extend into thespaces between runs and being free of said flanges at the bends, saidflanges on the runs being severed transversely at a plurality oflocations to provide wings spaced longitudinally of the stock, and thewings'on adjacent runs extending toward each other crosswise of thespace between adjacent runs, said wings being fashioned into an angularposition for deflecting and setting up turbulence in the ambient fluid.

2. A heat transfer device comprising, a length of metal stock having atubular formation fashioned into a plurality of spaced runs with theruns connected by reversely bent parts of the stock, said stock havingflanges on the runs thereof positioned'so that the flanges extend intothe spaces between runs and being free of said flanges at the bends,said flanges on the runs being severed transversely at a plurality ofloca runs extendingtoward each other crosswise of tions toprovide aplurality of wings along the length of the, stock, and the wings onadjacent the space between adjacent runs, said wingsbeing fashioned intooppositely angular positions for deflecting and setting up turbulence inthe I ambient fluid.

3. A heat transfer device comprising, a strip of metal stock having atubular formation and' with four longtiudinally extending flanges Ithereon spaced substantially 90 apart, said stock being fashioned into aplurality of runs, with the runs connected by reversely bent parts ofthe stock, two of the flanges which lie on the inside and outside of thebends being removed at the bends, and said two flanges on the runs beingsevered to provide wings, said wings being fashioned out of thenormalplane of the corresponding flange to provide passageways forambient fluid between the runs and to provide surfaces for contact withthe fluid.

4. A heat transfer device comprising, a strip of metal stock having atubular formation and with four longitudinally extending flanges thereonspaced substantially 90 apart; said stock being fashioned into aplurality of runs, with the runs connected by reversely bent parts ofthe stock, two of the flanges which lie on the inside and outside of thebends being removed at the bends, and said runs being so spaced that thesaid two flanges normally substantially meet edge to edge, the said twoflanges being cut at spaced locations to proved wings, and said wingsbeing fashioned to provide passageways for ambient fluid through stock,two of the flanges which been the inside and outside of the bends beingremoved at the bends, and said two flanges on the runs being severed toprovide wings, said wings being fash ioned out of the normal plane ofthe corresponding flange to provide passageways for ambient fluidbetween the runs and to provide surfaces for contact with the fluid, andsaid wings being angularly disposed for deflecting and setting upturbulence in the fluid passing therethrough.

6. A heat transfer device comprising, a strip of metal stock having atubular formation and with four longitudinally extending flanges thereonspaced substantially 90 apart, said stock being fashioned into aplurality of runs, with-the runs connected by reversely bent parts ofthe stock, two of the flanges which lie on the inside and outside of thebends being removed at the bends, said two flanges on the runs beingsevered to provide wings. said wings being fashioned out of the normalplane of the corresponding flange to provide passageways for ambientfluid between the runs and to provide surfaces for contact-with thefluid, and said wings being oppositely angularly disposed for deflectingand setting up turbulence in the fluid passing therethrough.

7. A heat transfer device comprising, a strip of metal stock having atubular formation and with four longitudinally extending flanges thereonspaced substantially 90 apart, said stock being fashioned into aplurality of runs, with the runs connected by'reversely bent parts ofthe stock, two of the flanges which lie on the inside and outside of thebends being removed at the bends, said two flanges on the runs'beingsevered to provide wings, said wingsbeing fashioned out tact with of thenormal plane of the'correspondingl flange v A toprovide passageways forambientfluid between theruns and to provide surfaces for contact withthe fluid, one of said, other flanges which faces the'on-coming. flow ofthe ambient fluid being relatively short, and the opposite. othervflange being relatively long for providing surface conthe ambient fluidas it passes from the device.

8. A heat I transfer, device comprising, astrip of extruded metal stockof-aluminum or aluminum alloy having a tubular formation and with fourlongitudinally extending flanges thereon spaced substantially-90 apart,said stock being fashioned-into a plurality of runs, with the runsconnected by reversely bent parts of the stock, two of the flanges whichlie onthe inside and outside of the bends being removed at the bends,

and sai two flanges on the runs being severed to provide wings, saidwings being fashioned out of the normal plane of the correspondingflange vwith each other, the ends of the tubular formationsbeingarrangedfor the inlet and outlet of a fluid, said wings providing a'contact area for an ambient .fluid.

- 10. A heat transfer device comprising, a strip of metal stock ofextruded aluminum or alumi-.

' .num alloyhaving a pluralityof tubular formations with-a webconnecting the formations, each tubular'formation having longitudinallyextending flanges which, together with the web, are all spacedsubstantially 90 apart, said stock being fashioned into a plurality ofspacedruns with theruns connected by reversely bent portions of thestock. the flanges being on the sides of to provide passageways forambient fluid between the runs and to provide surfaces for contact withthe fluid.

9. A heat transfer device comprising, a strip of metal stock of extrudedaluminum or alumi- 1 num alloy having a plurality of tubular formationswith a web connecting the formations, each 1 tubular formation havinglongitudinally extending flanges which, together with the-web, are allspaced substantially 90 apart, said-stock .being fashioned into aplurality of spaced runs with the runs connected by reversely bentportions of the stock, the flanges, being onthe sides of the tubularformation so as to extend into the spaces between runs, and, thereversely bent portions be= ing free of :flanges, the said flanges onthe runs being cut at a plurality of locations and fashioned to provideheat transfer wings, the wings on adjacent runs being substantially incontact formations being arranged for the inlettand outlet of a fluid,said wings providing a contact area for an ambient fluid, and a framehaving side portions with apertures therein through which thereversely'bent portions extend.

11. A heat transferdevice or the like compris ing, a strip of metalstock having a tubular formationwith four exterior flanges thereonspaced substantiallyl apart, said stock being fashiioned into apluralityof runs with the runs connected 'bii reversely bent parts of the stock,two

of the flanges which are on the inside and the outside of the bendsbeing removed from the bends ang'i said twoflanges on the runs being cutto provideinte'gralheat transfer fins, the other two flanges of thestock being. partially severed from thestocl; at the bends and beingfashioned to extend'in a direction substantially perpendicular to theruns and'belng secured together adform a frame structure.

jacentthe bends to

